It looks like a charming vintage photograph of a barely grinning young girl — but it’s not, according to national soul treasure Mavis Staples, talking about the cover shot for her latest EP for ANTI-Records, Your Good Fortune. It’s her kindergarten school portrait from 1944, and it comes with some emotional baggage.

“I call that picture my ‘Mona Lisa’ — I wouldn’t show my teeth because I had four teeth out,” she says. “And my brother Purvis would call me Charlie Snag, and I would cry and tell daddy, ‘Daddy! Purvis is calling me Charlie Snag again!’ And Pops would say, “Purvis, don’t treat her like that! That’s your baby sister!'”

The only upside, she adds, was the tooth-fairy reimbursement she received for said chompers underneath her pillow.

The names almost need no introduction. The late Pops Staples was the leader of the legendary R&B/Gospel family band The Staple Singers, formed six years after that awkward shot was taken, with Mavis and her siblings Cleotha, Yvonne, and, of course, pesky Purvis. Initially dubbed God’s Greatest Hitmakers, the group — thanks to Pops’ friendship with Martin Luther King, Jr. — aligned itself with the civil rights movement in the ’60s, then started hitting the secular charts in the ’70s with definitive No. 1 hits such as “I’ll Take You There” and “Let’s Do It Again.” Mavis Staples’ solo career began in 1969, and was recently revitalized with “You Are Not Alone” and “One True Vine,” two comebacks produced by fellow Chicagoan — and huge fan — Jeff Tweedy from Wilco, the first of which won the singer her first Grammy for Best Americana Album in 2011. On Sept. 25, Mavis Staples plays the Fillmore.

Researching this artist’s remarkable career — from grade school on, through her friendships with Mahalia Jackson, Gladys Knight, Bob Dylan, and even Barack Obama — has been made easier now, via Mavis!, Jessica Edwards’ exhaustive and loving new documentary that premiered at Austin’s South by Southwest Film Festival this year. Staples, now 76, was moved to tears when she saw the final cut.

“And they almost had to fight me to do it, because at first I told my manager, ‘Look, I have told my storysomany times,'” she says. “But Jessica did a wonderful job — she found so much on The Staple Singers, from our beginning, with shots in there from when I was a little kid, a teenager.” The movie also features fond testimony from other performers that Staples influenced, including Dylan, Bonnie Raitt, Marty Stuart, and Harry Belafonte.

“The last thing we learn in life is other people’s perceptions of us,” the writer George Eliot once wisely noted. Staples adores this quote. And the idea that, thanks to Mavis!, she won’t have to wait that long. “It’s the history of my family — onscreen!”she marvels. “And it’s going to leave us really documented, so any kid can watch it and learn about us, Dr. King, and the movement, because it’s educational, too.” She’s still closely in touch with her past — together, she and Tweedy just put the finishing touches on Don’t Lose This, which would become Pops Staples’ final, posthumous album. But she also has her eye firmly on the future.

Scanning through current rock videos last year, she stumbled upon a young singer that gave her the chills — neo-soul stylist Son Little, also signed to the ANTI- imprint. She contacted him and asked if he might want to contribute a song.

Little not only sent Staples two Stax-Volt-vibrant originals — “Fight” and “Your Good Fortune,” which would anchor her EP — he oversaw the sessions as well, and her updated covers of two Staple Singers chestnuts, “Wish I Had Answered” and “See That My Grave Is Kept Clean.”

“When I first heard Son Little, the kid just had so much soul in his voice, he was a throwback to the Sam Cooke era, and classic Gospel, too,” she says in praise of her benefactor, who will soon be issuing an eponymous full-length, following his Things I Forgot EP. “And then I learned that his dad was a preacher, and I said, ‘Iknewthat boy had been to church!’ I could tell. So he came to Chicago, we went into the studio, and we’ve been friends ever since.”

Staples attributes her longevity to staying curious, always hungry for knowledge. Then again, she admits, “I’ve been out here a long time — 65 years — and I’ve seen so many places, and seen so much, it’s hard for me to get excited anymore. But when I see some kid like this Son Little? Now that excites me.” Still, she’s been blindsided by the evening news lately. “I’ve been watching Mr. Donald Duck… Oh, Lord! I mean Mr. Donald Trump,” she chuckles. “And it’s so surprising to me that a man of his caliber would talk like he does. And look down on people the way he does. As rich as he is!”

Will Staples be hanging out with President Obama, once he’s out of office? She guffaws at the notion. “Heck, no!” she says. “I probably won’t even be able tofindObama. We’re wondering if he’s going to live in Chicago or New York. It’s hard enough for me to see him now. So I know that once he’s out, I won’t be seeing him anywhere. And I know he can’t wait to get out of there, and I can’t wait for him togetout of there. The way they have mistreated him? And he’s done good.”

“And that’s what I would love to say to him,” Staples concludes, her activist hackles rising. “You didgood,Obama. Hold your head up, and your chest out! And if he ever calls me? I will answer.”